Oxygen service regulators

  • Safety Flash
  • Published on 28 May 2019
  • Generated on 7 November 2025
  • IMCA SF 12/19
  • 2 minute read

What happened?

It was discovered on several dive sites that regulators being used on high pressure gas quads of greater than 25% oxygen were not actually suitable for oxygen service.  Component parts of an oxygen system are said to be fit for oxygen service when they are both:

  • oxygen clean
  • constructed from components with high temperature resistance.

While the items had been delivered oxygen clean to the proper specification, some of the component materials were found not to be oxygen compatible.  Additionally, the regulator type supplied was a venting model, whereas a non-venting model was recommended.

What was the cause?

Product knowledge was insufficient/incomplete on the part of the buyer at the time of purchase.

What actions were taken?

A thorough reading of specifications should be made before selection of a product.  The understanding that the regulators were delivered clean for Oâ‚‚ service convinced the end users that they were suitable.

The certificate which the supplier includes separately, if requested and at additional cost, states:

“Note: Specifications of materials in regulators for Oxygen Service is the USER’S RESPONSIBILITY.”

Our Member has performed a management of change (MoC) procedure for the change-out of all affected company regulators (on quads and in dive panels).  A risk assessment was performed, and the results indicated the need to retrofit fully compliant oxygen service regulators that are not only oxygen clean, but also constructed of oxygen compatible materials.  However, it was considered that there were enough mitigations in place to retain the use of the venting model for select purposes such as gas quads in designated no hot work areas on open decks.

Over the course of the transition, company personnel and suppliers are being informed about the change and the reasons for it.

IMCA Members are advised to ensure that all regulators or other components intended for use within oxygen systems are fit for oxygen service, i.e. that they are oxygen clean and made from oxygen compatible material.

Latest Safety Flashes:

Bunker hose obstructing emergency exit

A bunker hose was discovered routed in a way that partially obstructed the stern emergency exit hatch.

Read more
Watertight door and emergency hatch found open at sea

Watertight doors and an emergency hatch were observed open in the ER (Engine Room) during an offshore audit.

Read more
ATSB: Undocumented modification contributed to steam burns

An unplanned pressure release resulted in burn injuries to three crew members.

Read more
Smoke in the battery room

Smoke was observed in the battery room of a vessel alongside.

Read more
Hull crack arising from vibration

A small vessel built of aluminium experienced vibration coming from the propeller.

Read more

IMCA Safety Flashes summarise key safety matters and incidents, allowing lessons to be more easily learnt for the benefit of the entire offshore industry.

The effectiveness of the IMCA Safety Flash system depends on the industry sharing information and so avoiding repeat incidents. Incidents are classified according to IOGP's Life Saving Rules.

All information is anonymised or sanitised, as appropriate, and warnings for graphic content included where possible.

IMCA makes every effort to ensure both the accuracy and reliability of the information shared, but is not be liable for any guidance and/or recommendation and/or statement herein contained.

The information contained in this document does not fulfil or replace any individual's or Member's legal, regulatory or other duties or obligations in respect of their operations. Individuals and Members remain solely responsible for the safe, lawful and proper conduct of their operations.

Share your safety incidents with IMCA online. Sign-up to receive Safety Flashes straight to your email.